1. Field of the Invention
The present invention relates to a solar energy collector.
2. Description of the Prior Art
Various types of solar energy collectors are known. Principally, known devices comprise a case support whose larger side is open and is arranged so as to face the sun. Within the interior of the case a sheet metal aborber is arranged which is either planar or cellular in structure and which absorbs solar radiation received and transmits the heat produced as a result of the radiation through a heat transfer fluid circulating under the sheet metal in a reservoir or canal. The reservoir or canal comprises a layer of sheet metal arranged under the absorber sheet metal, in a sealed fashion, preferably along the entire circumference of the absorber. Thermal insulation is generally provided beneath the sheet metal so as to limit thermal losses from the collector. The open face of the case is either left alone or covered with one or several transparent planar panels. The panels which are planar, but which may also be rounded, serve to protect and insulate the absorber while creating a greenhouse effect which favors heat transfer to the heat transfer fluid. The collectors are arranged either in a fixed fashion, or in a rotatable fashion so as to maintain their orientation perpendicular to the sun in the course of the earth's rotation.
These known solar energy collectors suffer from various inconveniences. Principally, it should be noted that the cost of the prior devices is relatively high because of the materials which must be used, particularly the absorber sheet metal and the reservoir or canal which contains the thermal fluid. Furthermore, the assembly of the prior devices requires that a seal be provided over the entire periphery of the device as well as over the various intermediate connections to the device so that deformation resulting from the high temperatures of the thermal transfer fluid do not adversely affect the device.
Yet another inconvenience of the prior art collectors is that if these collectors are not provided with a device for changing their orientation, a substantial portion of the rays will be reflected by the transparent closure panel and will, as a result, be lost. Naturally, this diminishes the yield of the collector. In those cases where the prior art collectors are provided with a transparent closure panel having a rounded surface, thus permitting it to capture solar radiation both very early or very late in the day, the radiation received cannot be collected and used because the space between the absorber and the rounded section of the closure panel is too great.